1. Field of the Invention
The present invention relates generally to an ink supply device in which an ink cartridge is removably installed in a cartridge installing section, and to an image recording apparatus including the ink supply device.
2. Description of the Related Art
Conventionally, in an image recording apparatus of what is called a tube supply type, an ink cartridge is disposed outside a carriage on which a recording head is mounted, and the ink cartridge and the recording head are connected to each other via a tube. In a cartridge installing section having an opening, for example, in a front surface of an apparatus body, this ink cartridge is installed in a horizontal direction via the opening (refer to Japanese Patent Application Laid-open No. 2009-132098). The cartridge installing section houses the ink cartridge in a removable manner. When the ink cartridge is installed in the cartridge installing section, an ink channel ranging from the ink cartridge to the recording head is formed. Ink is supplied to the recording head from the ink cartridge through the ink channel.
In order to allow the ink stored in the ink cartridge to flow out, a hollow needle called an ink needle or the like is provided in the cartridge installing section. Inserting the ink needle to the ink cartridge allows the ink stored in the ink cartridge to flow out through the ink needle.
In the cartridge installing section, there is sometimes provided a sensor for detecting a remaining amount of the ink stored in the ink cartridge (Japanese Patent Application Laid-open No. 2007-15393). Further, a sensor for detecting whether or not the ink cartridge is installed is sometimes provided in the cartridge installing section. Among image recording apparatuses of what is called an on-carriage type in which an ink cartridge is installed on a carriage, there is also known an apparatus in which an optical sensor provided below the carriage detects a remaining amount in an ink cartridge mounted on the carriage moving above the optical sensor.
Disposing the aforesaid various kinds of sensors at or adjacent to the ink needle has an advantage that the ink cartridge is installed in the cartridge installing portion can be accurately detected. However, if the various kinds of sensors, substrates, and so on are disposed near the ink needle and the tube, the ink leaking from the ink needle or the tube adheres to the sensors or the substrates, for example, during the transport of the image recording apparatus from a user to a service center, which might be a cause of a trouble of the sensors and the substrates. Such a problem is likely to occur when the sensors and the substrates are disposed on a lower side of the ink needle and the tube in the vertical direction (gravity direction). Thus, the layout of the sensors and the substrates in the cartridge installing section is restricted by the relation with the arrangement of the ink needle and the tube, and generally, disposing the sensors and the like below the ink needle and the like has been avoided. Incidentally, in the image recording apparatus of the on-carriage type, the sensors are sometimes disposed below the ink cartridge, but since the ink cartridge is not always present above the sensors, there is little risk that the ink leaking from the ink cartridge and the like adheres to the sensors.